Do it by splitting middle term.
Then you will be able to get factors . You can learn how to split middle term by searching videos on you tube or any site.
Answer:
$300
Step-by-step explanation:
10+15=25% or 1/4
400/4=100
400-100=300
The answer would be 10. Im not quite sure if thats the answer, im sorry if i get it wrong. Otherwise i hope this helped you! :)
If you have a Scientific calculator you can type this in